1. Field of the Invention
The invention relates to a bidirectional transmission system for the bidirectional wireless transmission of spectrum spread data between any two points.
2. Summary of the Prior Art
When discreet, confidential and jamming resistant transmission of data is required, it is known to make use of the techniques referred to as wide band spectrum spreading. In the case of the direct sequence spreading technique, the useful signal to be transmitted modulates a spreading code in the form of a pseudo-random sequence of binary values, the rate of which is far higher than the band width of the useful signal. On reception, the received coded signal is correlated with a pseudo-random code generated by the receiver of which the setting makes it possible, by means of a synchronizing device, to restore the initial useful signal.
However, this confidential data transmission is unidirectional and therefore, if a two way transmission is desired, it is necessary to make use of two separate identical links.